Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 68ac774486c80dede87a4b4fe5ce075d0261a76a91bf886b95ddfa2a6972a3b3:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

error: pre-condition failed: listing has already been purchased
   --> 4eb8a10cb9f87357.NFTStorefront:243:16